As polymer compositions having excellent oxidation deterioration resistance, there are disclosed in, for example, U.S. Pat. Nos. 3,767,628 and 3,658,769 copolymers of butadiene or butadiene plus a vinyl compound and a specific amide or imide compound copolymerizable with them. However, these copolymers are not sufficient in oxidation deterioration resistance.
In order to meet the demands mentioned above, the present inventors have conducted extensive research to find a novel polymer composition.